This invention pertains to break-away devices and has particular relevance to the utilization of such devices in a gripper arm assembly of an inserting machine.
In serting machines, such as that disclosed in U.S. Pat. No. 2,325,455 to A. H. Williams (incorporated herein by reference), gripper arms having gripper jaws are employed to extract pieces of insert material from supply stations and to deposit the extracted pieces on a transport means. In this respect, a plurality of gripper arms, each associated with a particular station, are simultaneously swung toward the supply stations by the rotation of a first shaft common to all the gripper arms. A second shaft (also common to all the gripper arms) then rotates and, through the operation of a crank disc and a control rod, thereby causes the gripper jaws at each station to engage a piece of insert material. The first shaft is then oppositely rotated so that the gripper arms extract the pieces. Lastly, the second shaft is oppositely rotated so that the jaws disengage the pieces of material and deposit the same on the transport means.
On infrequent occasion pieces of material may jam occur at a supply station. An operator may endeavor to rectify the jam by using either his hand or a tool to retrieve the jammed piece of material. Since gripper arms such as those described above generally are quite durable and operate with great rapidity, correction of a jam in this manner presents several potential problems. First, should an operator interpose his hand into the path of the gripper arm to retrieve the jammed piece, there is a possibility that the swift, rigid gripper arm would injure the operator's hand, arm, or wrist. Secondly, should an operator interpose a tool, there is a further possibility that the tool may damage the gripper arm.
Therefore, an object of this invention is to provide a break-away device that temporarily yields upon impact. Break-away devices per se are not new and are of many diverse types. One such break-away device is illustrated in U.S. Pat. No. 3,561,281 to Wilfert, which discloses a floor-mounted automobile stick shaft having a coupling positioned on an inclined plane between two shaft portions with a spring-loaded ball locking the coupling in place. The coupling yields when the stick shift is subjected to a shock-like load along its longitudinal axis.
Existing break-away devices, including the Wilfert device, do not break-away under lateral impact so as to prove compatible with the operation of an inserting machine. Therefore, an advantage of this invention is the provision of a gripper jaw assembly having a gripper arm that temporarily breaks away upon lateral impact. Accordingly, the invention advantageously promotes shop safety and prevents damage to costly machinery.